1 // -*- C++ -*-
2 //===----------------------------------------------------------------------===//
3 //
4 //                     The LLVM Compiler Infrastructure
5 //
6 // This file is dual licensed under the MIT and the University of Illinois Open
7 // Source Licenses. See LICENSE.TXT for details.
8 //
9 //===----------------------------------------------------------------------===//
10 
11 // UNSUPPORTED: c++98, c++03, c++11, c++14
12 
13 // XFAIL: with_system_cxx_lib=macosx10.12
14 // XFAIL: with_system_cxx_lib=macosx10.11
15 // XFAIL: with_system_cxx_lib=macosx10.10
16 // XFAIL: with_system_cxx_lib=macosx10.9
17 // XFAIL: with_system_cxx_lib=macosx10.7
18 // XFAIL: with_system_cxx_lib=macosx10.8
19 
20 // <variant>
21 
22 // template <class ...Types> class variant;
23 
24 // constexpr variant() noexcept(see below);
25 
26 #include <cassert>
27 #include <type_traits>
28 #include <variant>
29 
30 #include "test_macros.h"
31 #include "variant_test_helpers.hpp"
32 
33 struct NonDefaultConstructible {
34   NonDefaultConstructible(int) {}
35 };
36 
37 struct NotNoexcept {
38   NotNoexcept() noexcept(false) {}
39 };
40 
41 #ifndef TEST_HAS_NO_EXCEPTIONS
42 struct DefaultCtorThrows {
43   DefaultCtorThrows() { throw 42; }
44 };
45 #endif
46 
47 void test_default_ctor_sfinae() {
48   {
49     using V = std::variant<std::monostate, int>;
50     static_assert(std::is_default_constructible<V>::value, "");
51   }
52   {
53     using V = std::variant<NonDefaultConstructible, int>;
54     static_assert(!std::is_default_constructible<V>::value, "");
55   }
56 #if !defined(TEST_VARIANT_HAS_NO_REFERENCES)
57   {
58     using V = std::variant<int &, int>;
59     static_assert(!std::is_default_constructible<V>::value, "");
60   }
61 #endif
62 }
63 
64 void test_default_ctor_noexcept() {
65   {
66     using V = std::variant<int>;
67     static_assert(std::is_nothrow_default_constructible<V>::value, "");
68   }
69   {
70     using V = std::variant<NotNoexcept>;
71     static_assert(!std::is_nothrow_default_constructible<V>::value, "");
72   }
73 }
74 
75 void test_default_ctor_throws() {
76 #ifndef TEST_HAS_NO_EXCEPTIONS
77   using V = std::variant<DefaultCtorThrows, int>;
78   try {
79     V v;
80     assert(false);
81   } catch (const int &ex) {
82     assert(ex == 42);
83   } catch (...) {
84     assert(false);
85   }
86 #endif
87 }
88 
89 void test_default_ctor_basic() {
90   {
91     std::variant<int> v;
92     assert(v.index() == 0);
93     assert(std::get<0>(v) == 0);
94   }
95   {
96     std::variant<int, long> v;
97     assert(v.index() == 0);
98     assert(std::get<0>(v) == 0);
99   }
100   {
101     using V = std::variant<int, long>;
102     constexpr V v;
103     static_assert(v.index() == 0, "");
104     static_assert(std::get<0>(v) == 0, "");
105   }
106   {
107     using V = std::variant<int, long>;
108     constexpr V v;
109     static_assert(v.index() == 0, "");
110     static_assert(std::get<0>(v) == 0, "");
111   }
112 }
113 
114 int main() {
115   test_default_ctor_basic();
116   test_default_ctor_sfinae();
117   test_default_ctor_noexcept();
118   test_default_ctor_throws();
119 }
120